Evaluating Trigonometric Functions

This tutorial teaches how to evaluate trigonometric expressions at various angles without using a calculator or unit circle. It covers the use of reference triangles, specifically the 30-60-90 and 45-45-90 triangles, to find sine, cosine, tangent, secant, and cotangent values for angles like 120 degrees, negative 45 degrees, and pi over 6. The video also includes practice problems for further learning.

What is the primary method used in this tutorial to evaluate trigonometric expressions?

• Using a calculator

• Using a unit circle

• Using trigonometric identities

• Using reference triangles

Which special triangles are essential for this tutorial?

• 30-45-60 and 60-90-120

• 30-60-90 and 45-45-90

• 30-30-120 and 60-60-60

• 45-45-45 and 90-90-90

How is the reference angle for 120 degrees determined?

• By subtracting 90 degrees

• By adding 90 degrees

• By adding 30 degrees

• By subtracting 30 degrees

What is the sine of 120 degrees?

• Square root of 2 over 2

• Negative 1/2

• Square root of 3 over 2

• 1/2

What is the cosine of 120 degrees?

• 1/2

• Negative 1/2

• Square root of 3 over 2

• Negative square root of 3 over 2

What is the tangent of 120 degrees?

• Square root of 3

• Negative 1

• Negative square root of 3

• 1

How do you determine the direction of rotation for negative angles?

• Upwards

• Counter-clockwise

• Downwards

• Clockwise

What is the cosine of negative 45 degrees?

• Negative 1/2

• Negative square root of 2 over 2

• Square root of 2 over 2

• 1/2

What is the sine of negative 45 degrees?

• 1/2

• Negative 1/2

• Square root of 2 over 2

• Negative square root of 2 over 2

What is the cosecant of negative 45 degrees?

• Negative 1

• 1

• Negative square root of 2

• Square root of 2